How to reset all data to defaulted / Zero entry

Hi Support, i have encounter an error “Action failed. Please refresh the page and retry.” when trying to update/save the postcode which have 500 record. find out that this is due to the php.ini is not enough to cater the memory or size… please advice how i can reset the postcode data all back to zero/defaulted value. i have try to uninstall and reinstall back seem the data still exists… your support are very much appreciated